Archive for the ‘Work File Only – Observer’s Challenge Reports’ category

NGC 5746, Galaxy in Virgo: June 2021 Observer’s Galaxy Report #149

June 14, 2021

Monthly Observer’s Challenge

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

June 2021

NGC 5746, Galaxy in Virgo

Sharing Observations and Bringing Amateur Astronomer’s Together

MONTHLY OBSERVER’S CHALLENGE

june-2021-observers-challenge-_ngc-5746Download

This month’s target

William Herschel discovered NGC 5746 on 24 February 1786 with his 18.7-inch reflector. His handwritten journal reads:” Extremely bright, much extended in the parallel, 8 or 9 arcminutes long, bright nucleus.”

A recent study by John Kormendy and Ralf Bender in the Astrophysical Journal presents NGC 5746 as a structural analog of our own galaxy. Both are “are giant, SBb–SBbc galaxies with two pseudobulges, i.e., a compact, disky, star-forming pseudobulge embedded in a vertically thick, ‘red and dead,’ boxy pseudobulge that really is a bar seen almost end-on.” According to the authors, the lives of these galaxies have been dominated by minor mergers and bar-driven evolution for most of the history of the universe. They place NGC 5746 at a distance of 26.7 Mpc (87 million light-years). https://ui.adsabs.harvard.edu/#abs/2019ApJ…872..106K/abstract

NGC 5746’s V(V_T) visual magnitude is 10.32 ± 0.13, and its surface brightness is 12.6. The galaxy’s visible extent through medium-size amateur telescopes under dark skies is in the vicinity of 7.4′ × 1.3′.

Roger Ivester: Observer from North Carolina

NGC 5746 – Galaxy in Virgo 

Date:  May 30, 2021

Telescope:  6-inch f/6 Newtonian 

Sketch Eyepieces:  16mm + 1.9x Barlow 

Magnification:  109x

Field of View:  0.60º

Very easy to locate and see using 46x, mostly in-part being only 20 arc minutes West of bright star,  3.7 magnitude 109 Virginis.  

My best view came at 109x, and presenting the galaxy as highly elongated, oriented almost perfectly N-S.  The core is fairly bright and elongated with faint extensions, coming to a point at both the N and S tips.  

For my sketch, I moved 109 Virginis out of the field of view, to reduce the extreme glare.  

Globular Cluster, M3, NGC 5272 in Canes Venatici: May 2021 Observer’s Challenge Report #148

May 19, 2021

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

May 2021

Report #148

Messier 3 (NGC 5272), Globular Cluster in Canes Venatici

Sharing Observations and Bringing Amateur Astronomers Together

Introductio

This month’s target

Charles Messier discovered M3 on 3 May 1764 with a 3.5-inch refractor. The French text of Messier’s catalog in the Connaissance des Temps translates into English as: “Nebula discovered between the Herdsman and one of the Hunting Dogs of Hevelius; it does not contain a star, the center is brilliant & its light imperceptibly fades, it is round; when the sky is good, one can see it with a refractor of one foot [at the time, telescopes were generally described by their length]; it is reported on the Chart of the Comet observed in 1779. Mémoires de l’Académie of the same year. Reexamined 29 March 1781, still very beautiful.”

According to William H. Harris’ Catalog Of Parameters For Milky Way Globular Clusters,

http://physwww.mcmaster.ca/~harris/mwgc.dat , M3 resides 10.2 kiloparsecs (~33,000 light-years) away from us and 12.0 kiloparsecs (~39,000 light-years) from the galactic center. It shines with an integrated V-magnitude of 6.19, and the spectral type of the integrated cluster light is F6. Does its color look slightly yellow to you?

May 2021 Observer’s Challenge Complete Report: may-2021-observers-challenge-_m3-2

Roger Ivester: Observer from North Carolina

M3 (NGC 5272) globular cluster in Canes Venatici 

Date: March 2021 

Telescope:  10-inch f/4.5 reflector

Eyepiece:  20mm + 2.8x Barlow 

Sketch magnification 160x

Field of View:  0.38º 

80mm refractor:  Little or no resolution, appearing mostly round with an intense core, and a fainter enveloping halo.  

10-inch reflector at 160x:  Excellent resolve of stars, mostly round, and with a large number of outlier stars beyond the halo.  A very interesting dark lane was noted in the SE-NE of the cluster.  

NGC 3226 and NGC 3227, Galaxies in Leo: April 2021 Observer’s Challenge Report #147

April 16, 2021

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

April 2021

Report #147

NGC 3226 & NGC 3227, Galaxies in Leo

Sharing Observations and Bringing Amateur Astronomers Together

This month’s target

William Herschel discovered this interacting galaxy pair on 15 February 1784 with his 18.7-inch speculum-metal reflector. His hand-written journal of the discovery reads: “Two nebulae almost close together. Perhaps 1½ or 2′ asunder, they are pretty considerable in size, and of a roundish form; but not cometic; they are very faint.” He also notes that on this night he first used: “A new, large object Speculum. It is very bright but not quite as distinct as my first, I shall however use it all the night.”

Together known as Arp 94, NGC 3226 and NGC 3227 are wedded in a gravitational dance 47.2 ± 0.2 million light-years away from us. Their complex dance has spawned a remarkable array of tidal tails as well as one tidal dwarf galaxy — a gravitationally bound condensation of gas and stars formed during the repeated encounters of the two parent galaxies.

The most recent journal paper on this captivating system can be perused here: https://www.aanda.org/articles/aa/full_html/2021/01/aa38955-20/aa38955-20.html

Observer’s Challenge Complete Report:

April 2021 OBSERVERS CHALLENGE _NGC 3226_NGC 3227

NGC 3226-3227: Interacting galaxy pair in Leo 

Date: March 2021

Telescope: 10-inch f/4.5 reflector 

Sketch Magnification: 114x

Field of View: 0.52º 

NGC 3227: Fairly bright, and easy to locate and see even at low magnification.  At 114x, elongated, oriented NW-SE, brighter central region, but subtle.  I first observed this galaxy pair and made my first sketch on April 14th 1993.   

NGC 3226: Much smaller and a fainter than NGC 3227, mostly round, but with a very slight elongation, NNE-WSW.  At 190x, and with averted vision, a stellar nucleus is visible.  Roger Ivester

Sue French: Observer from New York

Through my 130-mm refractor at 23×, I see a moderately faint glow at the position of the interacting pair NGC 3226 and NGC 3227. At 63× it becomes evident that two galaxies dwell here. Although their halos blend together, each harbors a small, distinct, brighter center. NGC 3227 is the brighter and larger galaxy of the pair, its oval façade leans east-southeast. Precariously perched on NGC 3227’s north-northeastern tip, NGC 3226 is wrapped in a halo that tips northeast.

NGC 3222 makes an appearance in the field of view 117×, 13′ west of the interacting duo. This little galaxy appears very dim and holds a weakly glowing, starlike nucleus. A 14th-magnitude star winks in and out of view near the galaxy’s SW×W edge. At this magnification, NGC 3226 grows brighter toward the center, while NGC 3227 displays an oval core with a prominent stellar nucleus. I estimate combined length of the pair to be about 41⁄2′.S

NGC 2685 – Galaxy In Ursa Major – March 2021- Observer’s Challenge Report # 146

March 18, 2021

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

March 2021

Report #146

NGC 2685, Galaxy In Ursa Major

Sharing Observations and Bringing Amateur Astronomers Together

march-2021-observers-challenge-_ngc-2685-2

Introduction

This month’s target

German astronomer Wilhelm Tempel discovered NGC 2685 in 1882 with an 11-inch refractor. Loosely translated, his discovery description reads: Good II-III; round; with a small star in the middle; stands 4′ south of a 10th-magnitude star. 

In the Hubble Atlas of the Galaxies, Allan Sandage states, “NGC 2685 is perhaps the most unusual galaxy in the Shapley-Ames catalogue.” While most astronomers would agree with this, there remain various opinions as to why. NGC 2685 is generally regarded as a polar ring galaxy wrapped in exterior hoops of gas and dust aligned nearly perpendicular to the plane of the galaxy’s lenticular disk. The rings may have been birthed by a merger and/or accretion event. A less touted viewpoint is that this galaxy is strongly warped, and the semblance of rings is merely the result of projection effects.

This perplexing galaxy lies roughly 50 million light-years away from us. As seen photographically, the unusual array of gas, dust, and resultant stars entwining the Helix gives rise to its name. The galaxy may also house a supermassive black hole. Sue French

Date: February 3, 2021

Telescope: 10-inch reflector

Sketch Magnification: 114x

Field of View: 1/2º

Description: Small, fairly bright, elongated NE-SW, brighter bulged center with a stellar nucleus. I last observed this galaxy on March 11, 1996, from the same location and telescope with almost identical results.

From my 5.0 NELM suburban location, it is very easy to locate and see with the 10-inch, but with very little fine detail. The stellar nucleus required a magnification of 183x, and averted vision. It was my plan to observe this galaxy with my 6-inch reflector for a comparison. Hopefully, I can make this comparison next year. Roger Ivester

NGC 1893 Open Cluster + IC 410 Emission Nebula – February 2021 Observer’s Challenge Report – Auriga #145

February 5, 2021

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina

&

Sue French, New York

February 2021

Report #145

IC 1893 and IC 410, Cluster and Emission Nebula in Auriga

Sharing Observations and Bringing Amateur Astronomers Together

Introduction

This month’s target

John Herschel discovered the open cluster IC 1893 in 1827 with the 18¼-inch reflector at Slough in Buckinghamshire, England. His handwritten journal reads: “Rich, coarse, scattered and straggling. It more than fills the field. The stars are 9…15 magnitude.”  The engulfing nebula, IC 410, wasn’t discovered until 1892, when Max Wolf found some new extended nebulae on photographic plates taken with a 6-inch Voigtländer portrait lens. My paraphrased translation of the pertinent section of his discovery says: The ribbon-rich nebula shown on the plates around the star cluster surrounds the star BD+33 1023 [HD 242908] should also be new. It largely encloses the whole group.

The nebula is roughly 11,000 to 12,000 light-years distant, and the adolescent cluster within it is at least 4-million years old.

Complete Report: February 2021 OBSERVERS CHALLENGE _NGC 1893 and IC 410

IC 348 – Open Star Cluster Plus Nebula – Perseus – January 2021 Observer’s Challenge Report #144

January 2, 2021

Compiled by:

Roger Ivester, North Carolina 

&

Sue French, New York

January 2021

Report #144

IC 348 – Cluster plus Nebula in Perseus

Sharing Observations and Bringing Amateur Astronomers Together

This month’s target

During his term as the first director of Dearborn Observatory, Truman Henry Safford discovered IC 348 on December 1, 1866, with the observatory’s 18.5-inch refractor. Safford published his observation in a table of objects found at Dearborn in the years 1866–1868. The table uses the alphabet-soup notation common to the era, which decrypted means: very large, very gradually brighter in the middle, pretty bright. Additionally, a note below that section of the table describes the object as “A loose cluster with nebula.” The combo appeared in the First Index Catalogue.

IC 348 has the dubious honor of bearing two IC designations. Edward Emerson Barnard independently discovered the nebula in 1893, and it was placed in the Second Index Calalogue as IC 1985, without anyone tumbling to the fact that it was already in the previous IC catalog. Unlike Safford, Barnard didn’t note the existence of the cluster within the nebula. 

IC 348 is thought to be roughly 1000 light-years away and a youthful 2–3 million years old. It holds about 500 stars, with brightest being hot, blue-white stars on the main sequence. The cluster’s visual magnitude is 7.3. By Sue French

january-2021-observers-challenge-_ic-348


M76 – Planetary Nebula in Perseus – December 2020 Observer’s Challenge Report: #143

November 29, 2020

Compiled by:

Roger Ivester, North Carolina 

&

Sue French, New York

December 2020

Report #143

M76, Planetary Nebula in Perseus

Sharing Observations and Bringing Amateur Astronomers Together

 

 

 

 

 

NGC 278 – Galaxy in Cassiopeia – November 2020 Observers Challenge: #142

November 15, 2020

Compiled by:

Roger Ivester, North Carolina 

&

Sue French, New York

November 2020

Report #142

NGC 278, Galaxy in Cassiopeia

Complete report: Click on the following link

November 2020 OBSERVERS CHALLENGE _NGC 278

NGC 7332/7339 Galaxy Pair in Pegasus: October 2020 Observer’s Challenge Report #141

October 15, 2020

Compiled by:

Roger Ivester, North Carolina 

&

Sue French, New York

October 2020

To view the complete report: Click on the following link…

october-2020-observers-challenge-_ngc-7332-39

The Veil Nebula In Cygnus – September 2020 Observer’s Challenge Report #140

September 13, 2020

  

MONTHLY OBSERVER’S CHALLENGE

Compiled by:

Roger Ivester, North Carolina 

&

Sue French, New York

September 2020

Report #140 

The Veil Nebula has long been modeled as the remnant of a supernova explosion that occurred within an interstellar cavity created by the progenitor star. However, a recent study by Fesen, Weil, and Cisneros (2018MNRAS.481.1786F ) using multi-wavelength emission maps indicates that the large-scale structure of the Veil Nebula is due to interaction of the remnant with local interstellar clouds. Employing Gaia DR2 data, the team determined an distance of 735±25 pc. 

This beautiful nebula bears several NGC designations. Its western arc, NGC 6960, runs through the naked-eye star 52 Cygni and is commonly called the Witch’s Broom. The tantalizingly intricate western arc is called NGC 6992 in the north, while the tattered southern reaches comprise NGC 6995. The brightest part of Pickering’s Triangular Wisp, which claims no NGC number, lies between the northern tips of the two great arcs. The discoverers of NGC 6974 (Lord Rosse) and NGC 6979 (William Herschel) gave these pieces positions that don’t correspond to anything obvious, but the names have been popularly tagged onto the northern and southern parts of the nebulosity just east of Pickering’s Triangular Wisp. As good a guess as any.

September 2020 OBSERVERS CHALLENGE _Veil Nebula